I learn something new about .ca domains all the time.
A poster at dnforum started a thread about LNL.ca, and revealed that Yellow Pages owns 1,530 LNL.ca domains that are the first three characters of postal codes in Canada. For example, H8Y.ca or V1L.ca. They bought most of these domains on Dec. 22, 2005 and continue to hold them.
The poster also stated that at that time in 2005, there were 1,630 total LNL postal codes, there are probably more today. The balance of the LNL.ca that Yellow Pages doesn't own are held by others.
I tried a few of these domains and they re-direct to ypg.ca, a Yellow Pages start page for English/French.
I've never seen Yellow Pages advertise any LNL.ca, you would think they have plans to eventually roll out some promotion to let people know they can enter the LNL.ca of an area they're searching within to find local information. I don't know how well that would work, postal codes don't often come up in everyday conversation, and if they do usually the full 6 character combination is used. But if YP puts their marketing muscle behind this type of promotion, they could get us used to searching this way.
This reminds me of a company, Marchex, in the US. Marchex owns most US postal codes in .com and .net, which are five numbers (unlike Canada, which uses letter/number combinations for postal codes). They have developped these postal code domains into local search portals. Enter a postal code of an area you're interested in, add the .com, and you're there.
I think if Canada had only numbers in postal codes this concept would interest me more. The letter/number combos just don't seem natural to use. The I and 1, and zero and O, and 5 and S can also lead to lots of typos, and hard to read combinations.